Fountain pen



Dec, 9, E952 J. A. MUSTARD 2,620,774

FOUNTAIN PEN Filed June s, 1948 5 sheets-sheet i J. A. MUSTARD Dec. 9, E952 FOUNTAIN PEN 3 Sheets-Sheet 2 Filed June 8, 1948 INVENTR. l JmeS/Vazrd,

y BY

J. A. MUSTARD Dec. 9, 1952 FOUNTAIN PEN 3 Sheets-Sheet I5 Filed June 8, 1948 Patented Dec. 9, 1952 FOUNTAIN PEN James A. Mustard, Janesville, Wis., assigner to The Parker Pen Company, Janesville, Wis., a corporation of Wisconsin Application June 8, 1948, Serial No. 31,763

(Cl. 1Z0-50) 3 Claims.

My invention relates to fountain pens and has to do particularly with an improved feed for feeding ink from the ink reservoir to the writing element.

An object of the present invention is to provide a fountain pen having a new and improved feed.

Another object is to provide a fountain pen wherein the feed of ink from the reservoir to the writing element does not depend for its operation upon the establishment and maintenance of any pressure balance between the air in the interior of the reservoir and the atmosphere.

Another object is to provide a fountain pen wherein the outlet leading from the interior of the ink reservoir is above the level of the ink in all positions of the pen whereby the pen is not subject to leakage, thus permitting the reservoir to be vented and thereby prevent leakage of the pen even when rapid changes in atmospheric pressure take place.

Another object is to provide a fountain pen wherein the ink feeds uniformly when the pen is in use, regardless of any changes in the temperature or pressure of the contents of the vpen or the atmosphere surrounding the pen.

A further object is to provide a fountain pen which may be carried in any position and which is not subject to leakage, even at relatively high altitudes.

A further object is to provide a fountain pen having a highly effective and reliable feed which is not subject to flooding or starving.

A further object is to provide a fountain pen which is simple in construction, reliable in operation, and which may be made economically.

Still another object is to provide a fountain pen having relatively few or no critical dimensions or adjustments and which can be assembled andl serviced by relatively inexperienced persons.

A further object is to provide a fountain pen which effectively maintains ink at the writing point for instant writing even when the writing point has been left exposed for relatively long periods of non-use.

A further object is to provide a fountain pen in which the necessity for close control of the flow of air into the pen reservoir is eliminated, the ink being under capillary control and the reservoir being fully vented at all times.

Other` objects and advantages of the invention will appear from the following description taken in connection with the appended drawings, wherein:

Figure l is an enlarged fragmentary, longitudinal, sectional view taken through the forward portion of a fountain pen constructed in accordance with this invention;

Fig. 2 is a View similar to Fig. 1, showing the rear portion of the fountain pen;

Fig. 3 is a fragmentary view of the forward portion of the feed of the pen shown in Fig. 1, certain of the parts being horizontally sectioned;

Fig. 4 is a transverse, sectional view taken along line 4-4 of Fig. 1;

Fig. 5 is a transverse, sectional view taken along line 5--5 of Fig. 1;

Fig. 6 is a transverse, sectional view taken along line 6-6 of Fig. 1;

Fig. 7 is an enlarged fragmentary, longitudinal, sectional view taken through the forward portion of another embodiment of my invention;

Fig. 8 is a similar view taken through the rearward portion of the pen in Fig. '7;

Fig. 9 is a fragmentary top plane View of the feed bar and a portion of the breather tube;

Fig. 10 is a transverse sectional view taken along line lll-I0 of Fig. '7;

Fig. 11 is a transverse sectional view taken along line Il-ll of Fig. 7;

Fig. 12 is an enlarged longitudinal, sectional View taken through the forward portion of a further embodiment of my invention;

Fig. 13 is a fragmentary view of a portion of the feed of the pen in Fig. 12, certain of the parts being horizontally sectioned;

Fig. 14 is a transverse sectional view taken along line Illld of Fig. 12; and

Fig. 15 is a transverse sectional view taken along line l5l5 of Fig. 12.

The present invention may be embodied in fountain pens of a number of different types and having various types of ink reservoirs, filling devices, writing elements and support means therefor, and the like. For the purpose of illustrating the invention, several different embodiments of my invention are disclosed herein, but it will be understood that the invention is not limited thereto.

Referring particularly to Fig. 1, the pen comprises a barrel 20 having an itnerior chamber defining an ink reservoir 2|. Secured in the forward .open end of the barrel 20 as by screw threads 22 is a plug orI body 23 having a generally cylindrical coupling portion 24 defining a chamber 25 which serves as an extension of the ink reservoir, and an end wall 26 which closes the forward end of the reservoir. A shell 21 is secured as by threads 28 on the body 23 and constitutes a forward extension of the barrel 20, serving to enclose the feed and a portion of the writing element hereinafter described; the barrel 20 and shell 21 together form the pen body or housing. A clutch ring 29 may be mounted on the plug 23 for frictionally receiving a slip-fitting cap in a known manner.

A writing element is carried at the forward end of the pen housing and is connected in ink feeding relation to the reservoir to receive ink therefrom in a manner hereinafter more fully described. While the writing element shown and described herein may take vtheform of a 'slitted nib of more or less conventional construction, it will be understood that the invention is not thus limited and that any suitable type of writing-element may be employed.

Carried by and preferably integral with` the plug 23 is a core 35 which extends substantially throughout the space 36 within theshell 21. The core 35 'has a bore 3'! adapted to frictionally receive and'mount a pen nib 438 of 'any suitable form, as for example one having a generally cylindrical body portion 39 whichis slitted as at 40 and is resiliently'held in the bore 31. The nib 38'is formed with a tapered Writing portion 4I which'extends through'an opening 42 in the forward end of the shell 21 and which is provided with the usual pierce 43 and slit 44 extending vtherefrom through the writing tip. The nib also is formed on its underside with an air vent notch 45 for a purpose which will hereinafter appear.

A feed bar 50 is provided which hasY a generally Icylindrical body portion Yl seated ina bore 52 in the plug 23, which extends'rearwardly of the bore 31. The feed bar extends through the nib 38 and has a reduced forward portion 53 adapted 'to bear against the forward end of the nib and which is spaced sufficiently from the bottom wall of the bore 42 to permit air to pass into the interior of the shell 21. The body 5I of the feed bar is of slightlysmaller diameter than the body portion of the nib, thereby providing an annular space 54 therebetween for a pui-pose which will hereinafter appear. A bore'which is of slightly greater diameter than the feed bar and approximately equal to the interior diameter of the nib provides an annular space 55 surrounding the feed bar rearwardly of the nib 33 and which communicates with the annular space 54 between the nib and feed bar.

For the purpose of feeding ink from'the reservoir 2| to the nib slit 44 andpierce 43, there is provided feed means which draws ink from the reservoir solely by capillary action and delivers it to the nib. The communication between the interior of the reservoir and the exterior of the pen is so arranged that no ink can pass freely from the reservoir in any position of the pen except that which is drawn 'from the reservoii` bythe capillary feed means and solely under capillary control, thereby insuring against leakage of ink from the reservoir under the influence of gravity or an unbalance of pressures between the interior of the reservoir and the exterior of the pen. The reservoir is Vcontinuously vented to atmosphere and the outlet from the reservoir is so positioned that it is always above the maximum level of the ink lin the reservoir, thereby preventing ink from either flowingout of or being forced out of the reservoir upon the establishment of an increased pressure in the reservoir.

To the foregoing end, a tube 69 is seated in a bore 6I in the end wall 26 and extends rearwardly into the reservoir 2| a substantial distance. The tube 6B is of such length that its inner end is disposed above the level of the ink in the reservoir and is open to the air in the resrvoir in all positions of the pen and no 'ink can flow from the reservoir directly into the tube 60 by reason of the effect of gravity when the pen s in pointdown position; neither can any'ink be forced into the tube 60 by an increase in pressure in the air in the reservoir such as might occur when the pen is carried to a high altitude or the contents of the reservoir are heated. The inner end of the tube 60 is located at the volumetric mid-point of the reservoir space so that it is above the ink level in any position of the pen.

For the purpose of feeding ink by capillary action from the reservoir to the nib slit 43, a wick B2 is provided which extends from the forward end of the reservoir 2l and through the tube 60 and a bore 63 communicating with the inner end of the tube Gt and thence through an arcuate slot or groove 64 formed in the upper side of the feed bar 5U from the rear end thereof to just short of the forward. end. The forward portion of the wick 62 is maintained in contact with the under side of the nib and in ink feeding relation to the nib slit 44 and pierce 43. The notch 64 may be slightly undercut as indicated at 65 in order to permit the wick to pass readily from the bore 63 into the notch 54 and to provide an air space therearound.

The wick may be made in any suitable manner which Will provide the desired capillary characteristics. The wick is formed of material which preferably is inert to inks of the types with which the pen is to be used and which is suitably wettable by such inks. While various materials may be used, I have found that nylon fibers or spun glass fibers have properties which make them highly desirable for use in my novel fountain pen. Preferably, the nylon or spun glass fibers are supported by a member, such as a Wire or wires, having suflcient rigidity to maintain the desired positioning of the wick, particularly that portion of the wick which extends in the ink reservoir. It is particularly desirable that the inner end of the wick shall extend to and be maintained in position in the forward end of the reservoir so that it will be submerged in the ink within the reservoir when the pen is in writing position even though only a small quantity of ink may remain in the reservoir; thus, it is possible to write out the reservoir substantially completely.

It Will now be seen that when the reservoir contains ink and the pen is held in Writingfposition, the lower or forward end of the wick will be immersed in the ink and, owing to the-capillary action exerted on the ink by the wick', ink will be drawn into the wick and will be raised along the portion of the wick which extends into the reservoir. Ink will be drawn from the aforementioned portion of the wick to completely saturate the wick so that a continuous body or column of ink extends from the free body of ink within the reservoir to the nib slit. Ink is drawn by capillary action from the wick-62 and into the nib slit 44 so that ink stands at all times in the nib slit and the pen is always in condition for instant writing. The wick preferably is made circular in form but preferably does not completely fill the several spaces in which it is located, such as the spaces between the feed bar and the nib, and between the feed bar and core, the bore 63 and the tube 68. lTherefore, an inlet channel is provided so that air to replace ink 'which is withdrawn from the reservoir'may be admitted through the opening 42 in the front end of the shell and pass 'into the annular space 54 between the nib and feed bar and thence through the slot 64, the bore 63 and the tube 60.

In order to prevent leakage of the pen should the wick be fully saturated and a sudden increase in pressure or temperature within the pen occur which might tend to force ink from the wick, an overflow collector is provided which preferably is disposed in the space 36 in the shell and is formed integrally with the plug 23. The overflow collector may take any suitable form but preferably it comprises a plurality of longitudinally-spaced capillary cells or spaces 1| which extend circumferentially around the core 35. The spaces 1| preferably are formed by cut` ting slots in the member forming the collector, leaving spaced, relatively thin circumferential fins 12 which serve to denne the slots 1|. The slots 1| are intersected by a slot 13 extending longitudinally of the collector and extending radially inwardly through the collector to intersect the annular spaces 5B and 55, thereby providing communication between the cells 1| and the aforesaid circumferential spaces which latter are of capillary width and are therefore in capillary ink feeding communication with the wick 62. Thus, should flooding or overflow conditions occur in the wick, any ink which tends to leak therefrom is drawn into the capillary spaces 5d and 55 and into the slit 13 and thence into the capillary cells 1 I. In order to permit the cells 1| to ll and empty readily, a breather slot 14 is provided which extends longitudinally of the collector, preferably diametrically opposite to slot 13 and which intersects all of the cells 1|. The breather slot 1li is of sufficient width so that ink is not drawn therein by capillary action but, due to the edge effect at the intersections of the cells 1 I with the slot 14, is retained in the cells, thereby leaving the breather slot 14 unobstructed by ink and permitting a free communication between each of the cells and the atmosphere by way of the breather slot 1d.

Any suitable type of filling mechanism may be provided for lling the ink reservoir to the desired extent. For example, a filling mechanism of the multiple stroke plunger type generally similar to that disclosed in U. S. Letters Patent to Arthur O. Dahlberg, Patent No. 1,904,358, granted April 18, 1933, may be provided. The tube 60 serves not only for the purpose hereinbefore described, but also as the breather tube through which ink is drawn in during the suction stroke and air is expelled during the compression stroke of the filling mechanism.

The present invention may be incorporated in fountain pens of many different types and, for the purpose of further illustrating the invention, it is shown in Figs. 7 to 11 as incorporated in a pen of the exposed nib type wherein the nib and feed bar associated therewith are mounted in and project from the forward end of a pen section.

Referring now particularly to Fig. '1, the pen includes a barrel |00 having threaded into its open end a plug or nipple |0| which serves as means for attaching a pen section |02 to the barrel. A clutch ring |03 may be provided, if desired. The plug I0| is formed with a rearwardly extending reduced extension |04 over which is secured the open forward end of a flexible sac |05 which sac, together with the interior |06 of the plug |0|, defines an ink-containing reservoir `space |01. The sac |05 may be of any suitable material and is secured to the extension |04, preferably by an adhesive.

Secured in the bore |08 in the forward end of the pen section |02 is a feed bar |09 having a body portion ||0 sitting snugly in the bore |06 and a tapered forward end portion A nib ||2 of conventional form and having an arcuate body portion ||3 with a tapered forward end |I4 provided with a pierce I I5 and a slit ||6 extending therefrom to the writing tip of the nib is frictionally wedged in the bore |06, the upper portion thereof being relieved as at ||1 to admit the nib.

Means are provided for feed-ing ink from the vreservoir to the nib slit I6 operating upon a generally similar principle to the feed means shown in Figs. 1 to 6 and described hereinbefore. Extending into the reservoir |01 is a tube |20 which extends through a bore I2| in the pen section |02 and a bore |22 in the feed bar |09 and is Seated in a reduced bore |23 but terminates rearwardly short of the forward end of the latter, as will be seen in Fig. '1. A wick |2d having its one end in the forward end of the reservoir |01 and preferably in the well formed by the bore |2|, extends through the tube |20 and has its forward end |25 extending out of the forward end of the tube |20 and into the bore |23 forwardly of the tube |20. Ink feeding communication between the forward end of the wick |24 and the nib slit I6 is provided by a longitudinally-extending slot I2!)` of capillary width cut into the feed bar |09 so as to intersect the bore |23 and to be in alignment under the nib slit ||6.

For the purpose of providing for overflow conditions and to prevent leakage of the pen when such conditions occur, a plurality of capillary cells |21 are provided which are formed by transversely-extending capillary slits arranged in a spaced series longitudinally of the feed bar |09 and intersected by the feed slot |26. Thus, should any ink be forced out of the feed wick hereinafter described and tend to flood the feed slot |26, such ink will be drawn by capillary action into the capillary cells |26.

Any suitable type of filling mechanism may be provided for filling the reservoir Iand there is shown by way of example a well-known type of mechanism of single-stroke type filling mechanism |28 employing a pressure bar |29 actuated by a plunger |36 which may be enclosed in a detachable blind cap |3|.

The pen is lled by actuating the filling mechanism in a known manner to compress the sac |05 forcing lair therefrom through the tube |20, the feed slit |26 and the nib pierce H5 and slit H6, and also through the slots |21 at the forward portion of the feed bar where the nib does not close these slots. When the plunger of the filling mechanism is released, the sac 05 expands to its original position and the suction thus created draws ink into the pen along the path just described but in ya reverse direction to that taken by the air during the compression of the sac. The rear end of lthe tube |20 is located so that it is above the maximum filling level of ink in the reservoir |1 and thus no ink can flow freely into the tube |20. However, when the pen is held in writing position, the ink which is in the reservoir stands at the forward end, and the forward end of the wick is immersed therein and draws ink thereinto to saturate the Wick. The forward end of the wick being in ink feeding relation with the feed slot "|26, -ink is drawn 'into fthe latter and V'delivered therebyto the nib "slit IIS. It will `'be noted yin this connection that the slot |26 passes Aunder the lowermost portions of the collector slots |21 and thus a 'continuous capillary path'is provided from the forward end of-the'wick |24to-thenib vslit ||6, Air to replace Vink Which-iswith'drawn in writing enters the -penthroughthe pierce (and through thefo'ri'vard -cells |21 when Vthey aref free 'of ink) and passesfalong the feed slot |26, particularly along-the Aupper portion thereof, and-entersthe tube E20'through which itpasses to the interioroft'he reservoir |01.

A further embodiment of my invention is illustrated in Figs. 12 to -15` which embodiment is somewhat similar to the form shown in Figs. 1 tof6 and thereforewill be described only in respect to those'features inwhich it differs therefrom, it being understood 'that wherethe strucdescribed in detail, it is similar to the structure of the rst described embodiment.

Y'Referring'now particularly-to Fig. 12, the pen comprises a barrel 290 having a shell 20| lcon-- nected thereto by a plug 2.2. The plug 2|l2is -generallysimilar to the plug-23 above described but has a rear extension 20S-for attachment of a sac 2M which, together with the interior of the plug 22, forms an ink reservoir25- It should 'be pointed out at this point'th-at in any of the several forms-of the invention illustrated herein, the reservoir maybe defined either bythe Ybarrel itself as illustrated inl Fig. 1 or by a sac as illustrated `in-Figs. 'Tand l2, an appropriate type of filling mechanism being' provided in each case.

In the-embodiment of the invention, -illustrated in Fig. 12, 'a core -ZES extends forwardly inthe shell 28| and carries a slitted nib 2G1- and a feed bar 208, the latter having a-generally cylindrical body portion 26S secured in a bore 2li! in the core 2M. A breather tube 2H is seated in a bore 252 in the rear end of the feed bar and extends through a bore 2| 3 in the forward wall of the plug 202 and into the reservoir 265. A wick V2M extends through the breather tube 2|| and into a recess 2|5 in the body of the feedbar 228 forwardly of the forward end of the lbreather tube 2| The forward end 2|6 of the wick 2|4 preferably is folded upon itself several times to insure that it is retained snugly in the recess 2|5.

The forward end of the Wick 2|4 is connected in ink feeding communication with the slit 2|1 of the nib by a slot 2|8 formed in the feed bar 2&8 preferably in the under side thereof and by an annular capillary space 2|S defined between the nib and feed bar by reason of the fact that the body 0f the feed 'bar is of slightly lesser diameter than the internal diameter of the nib.

If desired, an overflow ink collector 222, generally similar to the collector described above, may be provided which includes a plurality of longitudinally-spaced, circumferentially-extending capillary cells 22| connected by a longitudinally-extending slot 222 to an annular space 223 defined between the body 209 0f the feed bar and the surrounding porion of the core 226 rearwardly of the rear end of the pen nib'291. An air breather slot 224 may be provided in the top portion of the collector 22D in a manner similar to that above described.

A suitable filling mechanism, of which only the pressure bar 225 is shown, may be provided, as above explained.

The pen is filled in the usual manner and when the filling mechanism is operated, ink is` withoutv requiring critical adjustments.

drawn in through the nib slit 2|`1 'and'pierce 226 and thence into the annular 'space l2|!! and through the slot 2|8 into the breather tube 2|| and thence into the reservoir 205. Ink is delivered from the reservoir to the nib slit by capillary action, the ink being drawn into the wick 2H andthence into the slot 2|8 and into the-annular space A2|9 from whence it is drawn by capillary action into the nib slit 2|1. -If desired, a slight clearance as indicated at 221 may be provided above the nib, which clearance is of capillary dimension 'and therefore will draw ink from the nib pierce and-willretain ink by capillary action above-the nib sothat the'nib slit is always wetted and -ink to replace that which evaporates from the nib slit-is always `available to prevent drying out of 'the'exposedportion of the nib. Air to replace ink which is withdrawn from the reservoir in writing enters the pen through the 'forward bore 22S vand passes through the annular space 219 and-the slot 2 I8 and thence into-the breather tube 2| From the foregoing, it will be seen that the present invention provides a fountain pen in whichthe ink reservoir is constantly vented-to atmosphere and accordingly, the operation of the pen is entirely independent of any changes which may take place in the atmospheric pressure or in the temperature of the contents of vthe pen. Therefore, the pen is not subject to leaking even when carried to highV altitudesl or when the pen is warmed as bythe heat of the hand.

-Tlie feed of ink from the reservoir to the nib is effected entirely by capillary action'and therefore is independent of any changes of temperature or pressure ofthe surrounding atmosphere or of the contents of the reservoir. Accordingly, the pen feeds with a uniform and controlled iiow of ink and is not subject to iiooding 'or starving. Since the ink is delivered to the nib slit by capillary action and no pressure balance between the interior of the reservoir and the exterior atmosphere is required, either for'retaining the ink in the reservoir or allowing it to feed to the nib, ink is maintained at all times at the nib and the pen is always in condition for instant writing. Should any evaporation of ink take place at the nib, the ink which evaporates is promptly and constantly replaced so that the nib is always maintained in wetted condition. The outlet from the ink reservoir may be and preferably is disposed above the maximum filling level of the ink in the reservoir and therefore ink will not flow from'the reservoir except as drawn therefrom by the Vcapillary'feed means. Consequently, the pen may be carried in any position without leaking. The overfiow collector provides insurance against even the slight leakage which might' possibly occurl in the event that'a sudden change in temperature or pressure occurs of such nature that it tends to force a small amount of ink from the saturated capillary feed member.

The present invention, furthermore, provides a pen Aconsisting of a relatively'small number of simple parts which may be assembled readily and In fact, the pen will operate satisfactorily even though the partsl mayVv not be accurately assembled or may become disarranged somewhat during use.

' I claim:

l. A fountain pen comprising a penbody having a reservoir therein, an air vent passage leading from said reservoir substantially at the volumetric mid-point thereof for constantly and freely 'maintaining thecontents of 'said reservoir substantially at atmospheric pressure and constituting the sole outlet from said reservoir, a filling mechanism for drawing ink into said reservoir solely through said passage, a writing element, and a formsustaining capillary ink feed element having a portion in said reservoir and extending into the forward portion of said reservoir and of sufficient rigidity to maintain its said portion in said forward portion of the reservoir and a portion eX- tending through and incompletely filling said vent passage and connected in ink feeding relation to said writing element for feeding ink from the reservoir by capillary action to the writing element.

2. The invention as set forth in claim 1, wherein the pen body includes a barrel open at its forward end and wherein is provided plug means closing the open end of said barrel, a' feed bar carried by said plug means and having a feed passage underlying said Writing element, and wherein said capillary feed element comprises a single wick extending continuously from said reservoir and into the feed passage in said feed bar.

3. The invention as set forth in claim 1, wherein the pen body includes a barrel open at its forward end and wherein is provided plug means closing the open end of said barrel and carrying 10 said writing element and over-flow collector means, including capillary cells, connected in inkreceiving relation to said feed element for receiving and storing ink which passes out of said reservoir in excess of the capacity of said feed element.

JAMES A. MUSTARD.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS 

